In wireless charging/power supply technologies, an energy sending device and an energy receiving device may perform energy transmission in a wireless manner. An existing wireless charging/power supply technology comprises an inductive coupling technology, a magnetic resonance technology, and a microwave energy transmission technology, and the like. The inductive coupling technology and the magnetic resonance technology are applicable to a short distance (centimeter level) wireless charging/power supply application scenario, whereas the microwave energy transmission technology may implement wireless energy transmission between an energy sending device and an energy receiving device in a long distance (the maximum distance is about 10 meters) application scenario.
FIG. 1 shows a working principle of a microwave energy transmission technology. In a wireless energy transmission system shown in FIG. 1, a wireless energy sending device 330a comprises a power source 300, a communications module 320, control logic 310, and a microwave array 101a, and a wireless energy receiving device 330b comprises a rectifier 340, control logic 350, a communications module 360, and a battery 370. The wireless energy sending device 330a transmits energy 301 to the wireless energy receiving device 330b in a wireless microwave manner. The microwave array 101a in the wireless energy sending device 330a comprises multiple phase adjustable emitter nodes, for example, up to 20000 emitter nodes, which are configured to send the energy 301, and the rectifier 340 in the wireless energy receiving device 330b receives the energy 301, so as to supply power to the battery 370 in the wireless energy receiving device 330b. At the beginning as a wireless energy transmission relationship starts to be established between the wireless energy sending device 330a and the wireless energy receiving device 330b, the microwave array 101a in the wireless energy sending device 330a adjusts phases of the emitter nodes one by one, so that each emitter node is adjusted to an optimal phase of performing wireless energy transmission to achieve an optimal wireless energy transmission effect. The foregoing process is referred to as a “phase calibration stage”. In the phase calibration stage, the communications apparatus 360 in the wireless energy receiving device 330b continuously sends a feedback signal to the communications apparatus 320 of the wireless energy sending device 330a by using a wireless data communication channel, so as to report, to the wireless energy sending device 330a, wireless energy transmission intensity (or wireless energy transmission power) received by the rectifier 340. The control logic 310 in the wireless energy sending device 330a adjusts the phases of the emitter nodes in the microwave array 101a one by one on the basis of the feedback signal, until the wireless energy transmission intensity reported by the communications apparatus 360 in the wireless energy receiving device 330b becomes maximal, and the phase calibration stage ends.
As shown in FIG. 2, when multiple wireless energy receiving devices Rx exist in a wireless energy transmission range of one wireless energy sending device Tx; for example, multiple terminal devices in a user's room need to be charged. The multiple wireless energy receiving devices Rx perform wireless energy transmission with the wireless energy sending device Tx in a sharing manner. In such a process, the wireless energy sending device Tx may perform energy transmission on the wireless energy receiving devices Rx in turn within a same or close transmission time. Every time when a wireless energy receiving device Rx that receives energy is switched, the wireless energy sending device Tx needs to perform phase calibration on all emitter nodes to achieve an optimal energy transmission effect.
However, in many scenarios, a user intends to keep relatively balanced states of charge for multiple charged devices, the foregoing sharing manner cannot meet the foregoing needs of the user.